The invention will be described in relation to its application to a wing or side mirror used on motor vehicles. However, it should be realised that the operating mechanism may be for use with other devices not necessarily mirrors, and therefore the invention should not be restricted to this specific application described hereunder.
Mirror heads are designed to rotate about a vertical pivot both forwards or backwards. The mirror head is held in its driving position by a detent which allows manual movement of the mirror housing to a parked position, deflection through being hit by passing traffic or colliding with an obstruction. With the mirror parked, the mirror head is substantially parallel to the side of the vehicle which in turn reduces the risk of impact or interference from passing pedestrians or other vehicles. It is particularly useful when the vehicle is parked in or travelling along narrow or congested roadways.
Typically, known automatic parking mechanisms are designed to drive the mirror head out of its normal operative position by applying sufficient torque to overcome the holding power of the mirror head detents. In addition, extra detents are required that have a greater breaking torque than the first set to enable manual breakaway of the mirror and associated drive means if the mirror head is impacted. Clearly, the drive mechanism will be required to provide sufficient torque to overcome the first set of detent mechanisms. This may be quite significant torque depending on how rigidly the mirror is to be held in either its operative or parked positions. This requires high power motors that have a high noise output. The mirror head, bracket and spigot also need to be designed to resist high loads and this normally means the use of metal components.
It is an object of this invention to provide a mechanism, and a particular mirror operating mechanism that allows automatic parking of the mirror head that overcomes the above problems. Preferably, the invention can be used to automatically park the mirror head when the vehicle ignition is switched off, and to then "retrieve" the mirror head to its deployed position once the ignition is again switched on.
It is also an aim of this invention to provide a drive means which will enable both linear movement and rotational movement of a mirror head or any other element that requires this combination of movement, be it a mirror head or otherwise.